Portable content player, content storage device, and method of synchronizing content state lists between portable content player and content storage device

ABSTRACT

A portable content player, a content storage device, and a method of synchronizing content between the portable content player and the content storage device, the method including: generating a first content state list for content stored in the content storage device and a second content state list for content stored in the portable content player; generating an execution list based on the first content state list and the second content state list; and matching the first content state list with the second content state list by executing a synchronization command included in the execution list on content selected to be synchronized. Accordingly, a user can automatically match the content state lists of the portable content player and the content storage device.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No.2006-108393, filed on Nov. 3, 2006 in the Korean Intellectual PropertyOffice, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Aspects of the present invention relate to a portable content player, acontent storage device, and a method of synchronizing content between aportable content player and a content storage device, and moreparticular, to a method and apparatus for editing a content state listof content stored in each of a portable content player and a contentstorage device and synchronizing the content state lists between theportable content player and the content storage device with respect tocontent that is selected to be synchronized.

2. Description of the Related Art

Conventionally, users directly manage all files in portable contentplayers, such as a portable multimedia player (PMP) and a mobile phone.To manage the files, the users search for desired files from a personalcomputer (PC) that is a mass media storage device. Thereafter, in orderto store the found files in a portable content player, the user mayconnect the portable content player and the PC to each other in awired/wireless manner, execute a transmission program, and store desiredmultimedia files in the portable content player. As a result, in orderto view a movie using the portable content player, most users mustrepeatedly perform the above-described procedures.

In addition, in order to continue to view multimedia data (e.g., amovie) that was interrupted during a reproduction in a content storagedevice (e.g., a PC), using a portable content player, the entire moviefile must be downloaded from the content storage device to the portablecontent player, and after the interrupted point of the downloaded moviefile is found, a portion subsequent to the interrupted point must beplayed.

SUMMARY OF THE INVENTION

Aspects of the present invention provide a method and apparatus toautomatically synchronize content state lists between a content storagedevice and a portable content player by connecting the content storagedevice and the portable content player to each other.

Aspects of the present invention also provide a method and apparatus tosynchronize content, whereby content interrupted during reproduction ina content storage device can be continued from the interrupted point ina portable content player.

According to an aspect of the present invention, there is provided amethod of synchronizing content state lists between a portable contentplayer and a content storage device having a content reproductionfunction, the method including: generating a first content state listfor content stored in the content storage device and a second contentstate list for content stored in the portable content player; generatingan execution list based on the first content state list and the secondcontent state list; and matching the first content state list with thesecond content state list by executing a synchronization commandincluded in the execution list on content selected to be synchronized.

The selected content may be selected to be synchronized by at least oneof the portable content player and the content storage device, and thesynchronization command included in the execution list may include atleast one of an update command of the first and/or second content statelist, a transmission command of a whole or a portion of the selectedcontent, and a delete command of the selected content.

The second content state list may include a transmission state, asynchronization state, and a reproduction state for each file of thecontent.

The second content state list may further include information on areproduction-interruption point of the content.

According to another aspect of the present invention, there is provideda method of synchronizing content state lists between a portable contentplayer and a content storage device having a content reproductionfunction, the method including: determining whether content to bereproduced in the content storage device is transmitted; transmittingand storing the content to be reproduced to the portable content playeraccording to the determination; if the content storage device stopsreproducing the content, determining whether the content is completelyreproduced; and if it is determined that the content is completelyreproduced, deleting the completely reproduced content from the portablecontent player and updating the content state list of the portablecontent player.

The method may further include deleting a reproduced portion of thecontent and updating the content state list of the portable contentplayer if it is determined that the content is not completelyreproduced.

The determining of whether the content is transmitted may includedetermining whether the content to be reproduced in the content storagedevice is transmitted based on whether the content to be reproduced iscontent that is selected to be synchronized, wherein the synchronizationis selected by at least one of the portable content player and thecontent storage device.

The content state list of the portable content player may include atransmission state, a synchronization state, and a reproduction state ofeach piece of content.

The content state list of the portable content player may furtherinclude information on a reproduction-interruption point of content thathas not been completely reproduced.

According to another aspect of the present invention, there is provideda content storage device having a content reproduction function andperforming content synchronization with a portable content player, thecontent storage device including: a content storage unit to storecontent; a content state list generator to generate and to update afirst content state list with respect to the content stored in thecontent storage unit; an execution list generator to generate anexecution list based on the first content state list and a secondcontent state list of the portable content player; and a synchronizationcontroller to match the first content state list with the second contentstate list by executing a synchronization command included in theexecution list on content selected to be synchronized.

If the content is reproduced when the content storage device isconnected to the portable content player, the synchronization controllermay store the content to be reproduced in the portable content player,wherein the stored content is content that is selected to besynchronized.

If the content is completely reproduced, the synchronization controllermay delete the completely reproduced content and update the first andsecond content state lists.

The content may be selected to be synchronized from at least one of theportable content player and the content storage device, and thesynchronization command included in the execution list may be at leastone of an update command of the first and/or second content state list,a transmission command of a whole or a portion of the selected content,and a delete command of the selected content.

The second content state list may include a transmission state, asynchronization state, and a reproduction state for each file of thecontent.

The second content state list may further include information on areproduction-interruption point of content that has not been completelyreproduced by the content storage device.

According to another aspect of the present invention, there is provideda portable content player capable of synchronizing content with acontent storage device having a content reproduction function, theportable content player including: a content storage unit to storecontent; and a content state list generator to generate and to update acontent state list with respect to the content stored in the contentstorage unit, wherein the content state list is updated by the contentstorage device with respect to content that is selected to besynchronized when the portable content player is connected to thecontent storage device.

The content may be selected to be synchronized from at least one of theportable content player and the content storage device, and the contentstate list may include a transmission state, a synchronization state,and a reproduction state for each file of the content.

The content state list may further include information on areproduction-interruption point of content that has not been completelyreproduced.

The portable content player may reproduce the content from thereproduction-interruption point by referring to the reproductioninformation.

According to another aspect of the present invention, there is provideda method of reproducing content in a first device that was partiallyreproduced in a second device, the method including: transmitting thepartially reproduced content from the second device to the first device;determining a reproduction-interruption point in the partiallyreproduced content; and reproducing the content from thereproduction-interruption point.

According to another aspect of the present invention, there is provideda method of synchronizing content state lists between a first storagedevice and a second storage device, the method including: generating afirst content state list for content stored in the first storage deviceand a second content state list for content stored in the second storagedevice; generating an execution list based on the first content statelist and the second content state list; and matching the first contentstate list with the second content state list by executing asynchronization command included in the execution list on contentselected to be synchronized.

Additional aspects and/or advantages of the invention will be set forthin part in the description which follows and, in part, will be obviousfrom the description, or may be learned by practice of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the invention will becomeapparent and more readily appreciated from the following description ofthe embodiments, taken in conjunction with the accompanying drawings ofwhich:

FIG. 1 is a block diagram of a portable content player and a contentstorage device according to an embodiment of the present invention;

FIGS. 2A and 2B illustrate content state lists of a portable contentplayer and a content storage device according to an embodiment of thepresent invention;

FIG. 3 illustrates an execution list according to an embodiment of thepresent invention;

FIG. 4 is a flowchart illustrating a synchronization method of a contentstorage device according to an embodiment of the present invention;

FIG. 5 is a flowchart illustrating a synchronization method of aportable content player according to an embodiment of the presentinvention;

FIG. 6 is a flowchart illustrating a method of reproducing content basedon reproduction information in a portable content player according to anembodiment of the present invention; and

FIG. 7 is a flowchart illustrating a case where content is completelyreproduced in a state where a portable content player is connected to acontent storage device according to an embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the present embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings, wherein like reference numerals refer to the like elementsthroughout. The embodiments are described below in order to explain thepresent invention by referring to the figures.

FIG. 1 is a block diagram of a content storage device 100 (such as a PC)and a portable content player 110 (such as a PMP or a mobile phone)according to an example embodiment of the present invention. Referringto FIG. 1, the content storage device 100 includes a content state listgenerator 101, a synchronization controller 102, a content storage unit103, a content reproduction unit 104, and a connection unit 105.Furthermore, referring to FIG. 1, the portable content player 110includes a content state list generator 111, a content storage unit 112,a content reproduction unit 113, and a connection unit 114. It isunderstood that aspects of the present invention disclosed as applyingto portable content players 110 are not limited to portable contentplayers 110, and may be applied to other content storage devices (suchas home audio equipment with content storage capabilities or personalcomputers).

The content state list generator 101 of the content storage device 100generates and/or updates a content state list with respect to contentstored in the content storage unit 103. With respect to each piece ofcontent, the content state list includes, but not limited thereto, acontent file name, a synchronization state regarding whethersynchronization is set, and a transmission state regarding whether acontent file has been transmitted from the content storage device 100 tothe portable content player 110. It is understood that, according toother aspects of the present invention, the content state list may alsoinclude additional information, such as a content file size, a contentfile type, and a reproduction-interruption point referring to a lastplayback interruption point.

For example, the content state list may further include a reproductionstate regarding whether the stored content has been reproduced. Inaddition, after an operation is performed on content in the contentstorage device 100 (e.g., an operation such as content reproduction orreproduction stop), the content state list generator 101 updates thecontent state list. Reproduction information, such as the reproductionstate and a reproduction-interruption point, may be included in anadditional information field of the content state list.

The synchronization controller 102 synchronizes the content state listof the content storage device 100 and a content state list of theportable content player 110 with respect to content that is selected tobe synchronized according to a synchronization command included in anexecution list. The synchronization of the content state lists matchesthe content state list stored in the content storage device 100 with thecontent state list stored in the portable content player 110.

The content storage unit 103 stores content that may, for example, bedownloaded from an external server via a network or the Internet 130.The stored content may be reproduced by the content reproduction unit104.

The connection unit 105 is connected to the portable content player 110via a wired/wireless connection device 120. For example, the connectionunit 105 may be a Universal Serial Bus (USB) interface, an infraredinterface, or a Bluetooth interface.

The content state list generator 111 of the portable content player 110generates and/or updates a content state list with respect to contentstored in the content storage unit 112. With respect to each piece ofstored content, the content state list includes, but not limitedthereto, a content file name, a synchronization state regarding whethersynchronization is set, a transmission state regarding whether a contentfile has been transmitted from the content storage device 100 to theportable content player 110, and a reproduction state. Reproductioninformation including a reproduction-interruption point may be includedin an additional information field of the content state list.

The content storage unit 112 stores content downloaded from the contentstorage device 100. The stored content is reproduced by the contentreproduction unit 113.

The connection unit 114 is connected to the content storage device 100via the wired/wireless connection device 120. For example, theconnection unit 114 may be a USB interface, an infrared interface, or aBluetooth interface.

FIGS. 2A and 2B illustrate content state lists 200, 201, 210, and 211 ofthe content storage device 100 and the portable content player 110according to an embodiment of the present invention. FIG. 2A illustratescontent state lists 200 and 210 before content is synchronized, and FIG.2B illustrates content state lists 201 and 211 after the content issynchronized. FIG. 3 illustrates an execution list according to anembodiment of the present invention.

An additional information field of each content state list may includereproduction information, such as information on areproduction-interruption point, a play time, a play count, DigitalRights Management (DRM), a license, and a codec of content, although notlimited thereto.

Referring to FIGS. 2A, 2B, and 3, a content storage device 100 (e.g., ahome PC) storing five pieces of movie content A to E and a portablecontent player 110 (e.g., a Portable Multimedia Player (PMP)) storingfour pieces of movie content A, C, D, and E are described as an example.Furthermore, it is assumed, as an example for purposes of thisdisclosure, that a user has set synchronization for A, B, C, and E ofthe content state list 200 of the content storage device 100 and A, C,D, and E of the content state list 210 of the portable content player110.

Referring to the content state list 210 of the portable content player110 before synchronization is performed, illustrated in FIG. 2A, theuser has received the content A but has not completely viewed thecontent A yet. The content C has not been completely received orreproduced. The contents D and E have been completely received andreproduced. The content state list 200 of the content storage device 100may be understood in the same manner.

If the content storage device 100 and the portable content player 110are connected to each other, the content storage device 100 reads thecontent state lists 200 and 210 of the content storage device 100 andthe portable content player 110. The content storage device 100generates the execution list illustrated in FIG. 3 based on the readcontent state lists 200 and 210.

Referring to FIG. 3, for the content D, it is necessary to update only asynchronization state of the content state list 200 of the contentstorage device 100. For the content E, since the portable content player110 has completely reproduced the content E, it is necessary to deletethe content E from the content state list 210. However, it is understoodthat, according to other aspects, the content E that has already beencompletely reproduced may just be omitted from the execution list,rather than deleted. For the content C, it is necessary to retransmit aportion, which has not been transmitted yet, to the portable contentplayer 110. For the content B, it is necessary to transmit the entireportion of the content to the portable content player 110.

If the execution list illustrated in FIG. 3 is edited, the contentstorage device 100 performs synchronization sequentially according tocommands included in the execution list. The sequence of synchronizationcan be set according to the importance of the content, an execution timeof each command, the priority of commands, and/or a user's preference.Thus, after the synchronization is performed, the content state lists201 and 211 of the content storage device 100 and the portable contentplayer 110 match with each other as illustrated in FIG. 2B.

FIG. 4 is a flowchart illustrating a synchronization method performed bythe content storage device 100 illustrated in FIG. 1, according to anembodiment of the present invention. Referring to FIG. 4, the contentstorage device 100 sets or initiates synchronization in operation S400.It is understood that the synchronization can be set by the portablecontent player 110 instead of the content storage device 100. That is,any one of the content storage device 100 and the portable contentplayer 110 can set the synchronization.

If the portable content player 110 is connected to the content storagedevice 100 in operation S401, the content storage device 100 reads acontent state list from the portable content player 110 in operationS402. The content storage device 100 edits an execution list for thecontent synchronization in operation S403 and performs the contentsynchronization according to the execution list in operation S404. Thecontent synchronization is sequentially performed in operation S405until the content synchronization is performed for all content includedin the execution list.

FIG. 5 is a flowchart illustrating a synchronization method performed bythe portable content player 110 illustrated in FIG. 1, according to anembodiment of the present invention. Referring to FIG. 5, the portablecontent player 110 sets or initiates synchronization in operation S500.The portable content player 110 determines in operation S501 whether theportable content player 110 is connected to the content storage device100. In operation S502, the content storage device 100 performs contentmanagement of the portable content player 110 if the portable contentplayer 110 is connected to the content storage device 100 in operationS501. That is, the portable content player 110 allows or transmitscontrol rights to the content storage device 100 to control the portablecontent player 110. Thus, the content storage device 100 can freelyupdate or delete a content state list and content stored in the portablecontent player 110. However, it is understood that according to otheraspects, the portable content player 110 may perform content managementof the content storage device 100.

FIG. 6 is a flowchart illustrating a method of reproducing content basedon reproduction information in the portable content player 110illustrated in FIG. 1, according to an embodiment of the presentinvention. Referring to FIG. 6, a user executes content that has notbeen completely reproduced in the portable content player 110 inoperation S600. The content reproduction unit 113 determines inoperation S601 whether reproduction information exists. If reproductioninformation exists in operation S601, the content reproduction unit 113applies the reproduction information in operation S604 in order toreproduce the content and reproduces the content based on thereproduction information in operation S602. Thus, the portable contentplayer 110 can reproduce the content starting from a point that has notpreviously been reproduced. If it is determined in operation S601 thatreproduction information does not exist, the content reproduction unit113 reproduces the content from the beginning of the content inoperation S602. The reproduction information may be stored in a contentstate list of the portable content player 110.

The portable content player 110 updates the content state list thereofwith respect to the reproduced content in operation S603. That is, ifthe content is completely reproduced, or if reproduction of the contentis interrupted, the reproduction information of the content is updated.

FIG. 7 is a flowchart illustrating a case where content is completelyreproduced in a state where the portable content player 110 illustratedin FIG. 1 is connected to the content storage device 100 illustrated inFIG. 1, according to an embodiment of the present invention. Referringto FIG. 7, a user reproduces content in the content storage device 100in operation S700 while the portable content player 110 is connected tothe content storage device 100.

If synchronization of the content being reproduced is set in operationS701, it is determined in operation S702 whether the content beingreproduced is stored in the portable content player 110.

If the content being reproduced is not stored in the portable contentplayer 110 in operation S702, the content storage device 100 transmitsthe content being reproduced to the portable content player 110 inoperation S703.

If the content being reproduced is stored in the portable content player110 in operation S702, it is determined in operation S704 whether thereproduction of the content has been stopped by the user.

If the reproduction of the content has been stopped by the user inoperation S704, it is determined in operation S705 whether the contenthas been completely reproduced. If the content has been completelyreproduced in operation S705, the portable content player 110 deletesthe content in operation S706, and updates a content state list thereofin operation S707. However, it is understood that according to otheraspects, the content that has already been completely reproduced mayjust be omitted from the execution list, rather than deleted.

If the content has not been completely reproduced in operation S705, theportable content player 110 updates the content state list thereof withrespect to the reproduction-interrupted content in operation S707, andthe content state list of the portable content player 110 may includereproduction information of the reproduction-interrupted content. Thus,thereafter, the user can reproduce the portion that has not beenreproduced based on the reproduction information in the portable contentplayer 110 as illustrated in FIG. 6. In this case, the user may deleteonly the portion of the content that has been reproduced when updatingthe content state list of the portable content player 110.

As described above, according to aspects of the present invention,content state lists can be automatically synchronized by connecting aportable content player to a content storage device. In addition, forcontent that has not been completely reproduced in the content storagedevice, a user can, conveniently, view the content from a point that hasnot previously been reproduced in the portable content player.

Although a few embodiments of the present invention have been shown anddescribed, it would be appreciated by those skilled in the art thatchanges may be made in this embodiment without departing from theprinciples and spirit of the invention, the scope of which is defined inthe claims and their equivalents.

1. A method of synchronizing content state lists between a portablecontent player and a content storage device having a contentreproduction function, the method comprising: generating a first contentstate list for content stored in the content storage device and a secondcontent state list for content stored in the portable content player;generating an execution list based on the first content state list andthe second content state list; and matching the first content state listwith the second content state list by executing a synchronizationcommand included in the execution list on content selected to besynchronized.
 2. The method as claimed in claim 1, wherein thegenerating of the execution list comprises: generating the executionlist if the portable content player and the content storage device areconnected to each other.
 3. The method as claimed in claim 1, whereinthe selected content is selected to be synchronized by at least one ofthe portable content player and the content storage device.
 4. Themethod as claimed in claim 1, wherein the synchronization commandincluded in the execution list is one of an update command of theselected content on the first content state list or the second contentstate list, a transmission command of a whole or a portion of theselected content, and a delete command of the selected content.
 5. Themethod as claimed in claim 1, wherein the second content state listcomprises a transmission state, a synchronization state, and areproduction state for each file of the content.
 6. The method asclaimed in claim 5, wherein the second content state list furthercomprises information on a reproduction-interruption point for each fileof the content that has not been completely reproduced.
 7. The method asclaimed in claim 1, wherein the first content state list comprises atransmission state, a synchronization state, and a reproduction statefor each file of the content.
 8. The method as claimed in claim 7,wherein the first content state list further comprises information on areproduction-interruption point for each file of the content that hasnot been completely reproduced.
 9. The method as claimed in claim 1,wherein the generating of the execution list comprises: comparing afirst content state for each file of the content on the first contentstate list to a second content state for the file of the correspondingcontent on the second content state list; and including thesynchronization command in the execution list for a first file if thefirst content state for the first file does not match the second contentstate for the first file.
 10. The method as claimed in claim 9, whereinthe including of the synchronization command comprises: including anupdate command in the execution list for the first file if a firstsynchronization state of the first file in the first content state listis different than a second synchronization state of the first file inthe second content state list; and including a transmission command inthe execution list for the first file if the first file is stored in thecontent storage device and not wholly stored in the portable contentplayer.
 11. The method as claimed in claim 10, wherein the including ofthe synchronization command further comprises: including a deletecommand in the execution list for the first file if a synchronizationstate, a reproduction state, and a transmission state of the first filein the second content state list are a finished state.
 12. The method asclaimed in claim 1, wherein the content storage device is a personalcomputer.
 13. A method of synchronizing content state lists between aportable content player and a content storage device having a contentreproduction function, the method comprising: transmitting contentreproduced in the content storage device to the portable content player;determining whether the content is completely reproduced in the contentstorage device if the content storage device stops reproducing thecontent; and deleting the content from the portable content player andupdating the content state list of the portable content player if thecontent is completely reproduced.
 14. The method as claimed in claim 13,wherein the transmitting of the content to be reproduced comprises:determining whether the content is stored in the portable content playerwhen the content storage device and the portable content player areconnected to each other; and transmitting the content to the portablecontent player if the content is not stored in the portable contentplayer.
 15. The method as claimed in claim 13, further comprises:deleting a reproduced portion of the content and updating the contentstate list of the portable content player if the content is notcompletely reproduced.
 16. The method as claimed in claim 14, whereinthe determining of whether the content is stored in the portable contentplayer comprises: determining whether the content is stored based onwhether the content is selected to be synchronized.
 17. The method asclaimed in claim 16, wherein the content is selected to be synchronizedby at least one of the portable content player and the content storagedevice.
 18. The method as claimed in claim 13, wherein the content statelists comprise a transmission state, a synchronization state, and areproduction state for each file of content in the content state lists.19. The method as claimed in claim 18, wherein the content state listsfurther comprise information on a reproduction-interruption point foreach file of the content in the content state lists that has not beencompletely reproduced.
 20. A method of reproducing content in a firstdevice that was partially reproduced in a second device, the methodcomprising: transmitting the partially reproduced content from thesecond device to the first device; determining areproduction-interruption point in the partially reproduced content; andreproducing the content from the reproduction-interruption point. 21.The method as claimed in claim 20, wherein the reproducing of thecontent comprises: reproducing the content from a beginning of thecontent if the reproduction-interruption point cannot be determined. 22.The method as claimed in claim 20, wherein the determining of thereproduction-interruption point comprises: determining whetherreproduction information comprising information on thereproduction-interruption point exists in a content state list.
 23. Themethod as claimed in claim 22, further comprising: updating the contentstate list after the reproducing of the content.
 24. The method asclaimed in claim 20, wherein the first device is a portable contentplayer and the second device is a content storage device.
 25. A methodof synchronizing content state lists between a first storage device anda second storage device, the method comprising: generating a firstcontent state list for content stored in the first storage device and asecond content state list for content stored in the second storagedevice; generating an execution list based on the first content statelist and the second content state list; and matching the first contentstate list with the second content state list by executing asynchronization command included in the execution list on contentselected to be synchronized.
 26. The method as claimed in claim 25,wherein the first storage device is a portable content player.
 27. Themethod as claimed in claim 25, wherein the second storage device is apersonal computer.
 28. The method as claimed in claim 25, wherein thematching of the first content state list with the second content statelist comprises: entrusting control rights of the first storage device tothe second storage device; and executing the synchronization command inthe second storage device.
 29. A content storage device having a contentreproduction function and performing content synchronization with aportable content player, the content storage device comprising: acontent storage unit to store content; a content state list generator togenerate and to update a first content state list for the content storedin the content storage unit; an execution list generator to generate anexecution list based on the first content state list and a secondcontent state list of the portable content player; and a synchronizationcontroller to match the first content state list with the second contentstate list by executing a synchronization command included in theexecution list on content selected to be synchronized.
 30. The contentstorage device as claimed in claim 29, wherein the content state listgenerator generates the execution list if the portable content player isconnected to the content storage device.
 31. The content storage deviceas claimed in claim 29, wherein: when the content storage device isconnected to the portable content player, the synchronization controllerstores the content in the portable content player; and the storedcontent is the content selected to be synchronized.
 32. The contentstorage device as claimed in claim 31, wherein if the content iscompletely reproduced, the synchronization controller deletes thecompletely reproduced content from the portable content player andupdates the first content state list and the second content state list.33. The content storage device as claimed in claim 29, wherein theselected content is selected to be synchronized by at least one of theportable content player and the content storage device.
 34. The contentstorage device as claimed in claim 29, wherein the synchronizationcommand included in the execution list is one of an update command ofthe selected content on the first content state list or the secondcontent state list, a transmission command of a whole or a portion ofthe selected content, and a delete command of the selected content. 35.The content storage device as claimed in claim 29, wherein the secondcontent state list and/or the first content state list comprises atransmission state, a synchronization state, and a reproduction statefor each file of the content.
 36. The content storage device as claimedin claim 35, wherein the second content state list and/or the firstcontent state list further comprises information on areproduction-interruption point of content for each file of the contentthat has not been completely reproduced by the content storage device.37. The content storage device as claimed in claim 29, wherein theexecution list generator generates the execution list by comparing afirst content state for each file of the content on the first contentstate list to a second content state for the file of the correspondingcontent on the second content state list, and including thesynchronization command in the execution list for a first file if thefirst content state for the first file does not match the second contentstate for the first file.
 38. The content storage device as claimed inclaim 37, wherein: the execution list generator includes an updatecommand in the execution list for the first file if a firstsynchronization state of the first file in the first content state listis different than a second synchronization state of the first file inthe second content state list; and the execution list generator includesa transmission command in the execution list for the first file if thefirst file is stored in the content storage device and not wholly storedin the portable content player.
 39. The content storage device asclaimed in claim 38, wherein the execution list generator includes adelete command in the execution list for the first file if asynchronization state, a reproduction state, and a transmission state ofthe first file in the second content state list are a finished state.40. The content storage device as claimed in claim 29, wherein thecontent storage device is a personal computer.
 41. A portable contentplayer capable of synchronizing content with a content storage devicehaving a content reproduction function, the portable content playercomprising: a content storage unit to store content; and a content statelist generator to generate and to update a content state list for thecontent stored in the content storage unit, wherein the content statelist is updated by the content storage device with respect to contentselected to be synchronized when the portable content player is in afirst state.
 42. The portable content player as claimed in claim 41,wherein the content state list generator generates and/or updates thecontent state list when the portable content player is not connected tothe content storage device.
 43. The portable content player as claimedin claim 41, wherein the first state is a state when the portablecontent player is connected to the content storage device.
 44. Theportable content player as claimed in claim 41, wherein the contentstate list is updated by matching the content state list to a contentstate list of the content storage device.
 45. The portable contentplayer as claimed in claim 41, wherein the selected content is selectedto be synchronized by at least one of the portable content player andthe content storage device.
 46. The portable content player as claimedin claim 41, wherein the content state list comprises a transmissionstate, a synchronization state, and a reproduction state for each fileof the content.
 47. The portable content player as claimed in claim 46,wherein the content state list further comprises information on areproduction-interruption point for each file of the content that hasnot been completely reproduced.
 48. The portable content player asclaimed in claim 47, wherein the portable content player reproduces thecontent that has not been completely reproduced from thereproduction-interruption point by referring to the reproductioninformation.